Integration of separation and photocatalysis using an inorganic membrane modified with Si-doped TiO₂ for water purification

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• 作者：Ning Ma ; Xie Quan ; Yaobin Zhang ; Shuo Chen ; Huimin Zhao
• 关键词：Si-doped TiO₂ layer ; Photocatalysis ; Separation ; Reactive azo dye ; Water treatment
• 刊名：Journal of Membrane Science
• 出版年：2009
• 出版时间：15 June 2009
• 年：2009
• 卷：335
• 期：1-2
• 页码：58-67
• 全文大小：1907 K

文摘

An unsymmetrical inorganic membrane with Si-doped TiO₂ layers was fabricated for the purpose of realizing filtration and photocatalysis in a single device in water purification process. Tetra-n-butyl titanate [Ti(OC₄H₉)₄, TBOT] and tetraethyl orthosilicate [Si(OC₂H₅)₄, TEOS] were used as precursors of TiO₂ and Si element source, and Si-doped TiO₂ photocatalytic layer was coated on a commercial Al₂O₃ membrane by sol–gel technique. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterization demonstrated that the Si-doped TiO₂ thin layer possessed nanoporous membrane structure. The results of UV–vis diffuse reflectance spectra (DRS) and X-ray diffraction (XRD) pattern indicated that a strong UV absorption of as-prepared membrane surface was ascribed to anatase phase of TiO₂ materials. The thickness controllability of Si-doped TiO₂ layer was conducted by repeated-coating procedure, and water permeability and polyethylene glycol (PEG) retention of membrane were related with thickness of the TiO₂ layer. The removal efficiency of model pollutant, dye Reactive Red ED-2B (RR ED-2B), was improved obviously using the membrane under UV irradiation in comparison with photocatalysis or membrane separation alone, which demonstrated that the model pollutant was separated and degraded simultaneously. The multifunctional performance of composite membrane hints this unit may become more powerful in water purification process.